The United States Department of Agriculture’s National Agricultural Statistics Service (NASS) conducts the June Agricultural Survey (JAS) annually. Substantial misclassification occurs during the ...prescreening process and from field-estimating farm status for nonresponse and inaccessible records, resulting in a biased estimate of the number of US farms from the JAS. Here, the Annual Land Utilization Survey (ALUS) is proposed as a follow-on survey to the JAS to adjust the estimates of the number of US farms and other important variables. A three-phase survey design-based estimator is developed for the JAS-ALUS with nonresponse adjustment for the second phase (ALUS). A design-unbiased estimator of the variance is provided in explicit form.
The United States Department of Agriculture's National Agricultural Statistics Service (NASS) conducts the June Agricultural Survey (JAS) annually. Substantial misclassification occurs during the ...pre-screening process and from field-estimating farm status for non-response and inaccessible records, resulting in a biased estimate of the number of US farms from the JAS. Here the Annual Land Utilization Survey (ALUS) is proposed as a follow-on survey to the JAS to adjust the estimates of the number of US farms and other important variables. A three-phase survey design-based estimator is developed for the JAS-ALUS with non-response adjustment for the second phase (ALUS). A design-unbiased estimator of the variance is provided in explicit form.
Each year, the National Agricultural Statistics Service (NASS) conducts the June Area Survey (JAS), which is based on an area frame. The JAS provides information on U.S. agriculture, including an ...estimate of the number of farms in the U.S. NASS also conducts the Census of Agriculture every five years in years ending in 2 and 7. The census, which uses both a list and the JAS area frame, also produces an estimate of the number of U.S. farms. In 2007, the two estimates were further apart than could be attributed to sampling error alone. Previous studies of the JAS identified misclassification of JAS sampled units as a source leading to an undercount in the number of farms in the U.S. Using data from the 2007 JAS and the 2007 Census, misclassification of tracts as agricultural or non-agricultural were identified. Research has also identified the estimation of agricultural activities for sampled tracts as another factor that contributes to the discrepancy in the JAS number of farms estimate. This research report presents methodology that adjusts for two known sources of error on the JAS: misclassification and estimation (which later will be addressed as non-response).
Each year, the National Agricultural Statistics Service (NASS) publishes an estimate of the number of farms in the United States based on the June Area Survey (JAS). Independent studies showed that ...the JAS number of farm indications have significant undercount due to misclassification. To adjust for this undercount, a follow-on survey to the JAS called the Annual Land Utilization Survey (ALUS) has been proposed. ALUS is designed and developed based on the Farm Numbers Research Project (FNRP). NASS conducted the FNRP in the fall of 2009 (Abreu, McCarthy and Colburn, 2010). ALUS samples from all JAS segments containing any estimated or non-agricultural JAS tracts. For a selected segment, all estimated and non-agricultural JAS tracts will be re-evaluated. The collection of eligible segments in a particular year will be called the ALUS population. The sample allocation of ALUS segments to each state-stratum combination considers two factors: the proportion of the ALUS population in the stratum and the proportion of the FNRP adjustment from non-agricultural tracts in the stratum. ALUS can be treated as a second phase to the JAS. The two-phase stratified design, JAS-ALUS, can be applied to any estimate produced by the JAS. However, ALUS has non-response. In this paper, methodology for a three-phase sampling design is developed by extending the two-phase sampling design methodology proposed by Sarndal and Swensson (1987). A general sampling design is allowed in each phase; that is, the inclusion probabilities in each phase are arbitrary. The estimator is unbiased, and an unbiased estimator for the variance is provided. Here, this method is applied to the two-phase JAS-ALUS with the third phase being response/non-response.
During the past three years, the National Agricultural Statistics Service (NASS) has made an effort to address, quantify, and adjust for an undercount in the number of farms indication from its ...annual June Area Survey (JAS), which is based on an area frame. This undercount is a direct result of the misclassification of agricultural tracts as non-agricultural. The 2007 Census of Agriculture mailing list (CML) was evaluated as a potential source to assess misclassification on the 2007 JAS. The CML was found to be a rich source from which to quantify the undercount of farms on the JAS. However, the CML is only available every five years, and misclassification on the JAS should be assessed each year. Independently of the area frame, NASS maintains a list of agricultural operators, referred to as the list frame. Yearly list-based samples are selected from the list frame. In addition, the list frame serves as the foundation for building the CML. The list frame is updated on an on-going basis and operators are categorized as either active or inactive. Although the CML includes all active records, some of these do not qualify as farming operations. This research report explores the potential of using the list frame on a yearly basis to assess the misclassification of farms on the JAS.
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